UK's Johnson lobbies for jailed aid worker

British Foreign Secretary Boris Johnson has held almost an hour of talks with Iranian President Hassan Rouhani after flying to Tehran to seek the release of a jailed British-Iranian aid worker.

"Both spoke forthrightly about the obstacles in the relationship and agreed on the need to make progress in all areas," said a spokeswoman for Britain's Foreign Office on Sunday after Johnson concluded what was only the third visit to Iran by a British foreign minister in the past 14 years.

The Foreign Office confirmed Johnson had raised "consular cases of dual nationals" during talks. These cases include Nazanin Zaghari-Ratcliffe, who Britain says was visiting family on holiday in April 2016 when she was jailed by Iran for attempting to overthrow the government.

The woman's husband later told Sky News that a court appearance scheduled in Iran for Sunday had been postponed. "I think I am very optimistic today," Richard Ratcliffe said.

He added that he hoped his wife would be home before Christmas but cautioned that there could still be setbacks.

"Without doubt having the foreign secretary there was a big thing. Without doubt the court case not happening is a big thing. There may be a number of big things that have to happen before she's home, but ... as I sit here, I am a lot more optimistic than I was."

Iranian state television had reported that "bilateral relations, the nuclear deal and regional developments made up the axis of the talks", between the president and Johnson.

The case of Zaghari-Ratcliffe has taken on domestic political importance after Johnson said last month that she had been teaching journalists in Iran, which her employer denies. Johnson later apologised. Opponents have called for him to resign if his comments lead to her serving longer in prison.

Johnson met Ali Akbar Salehi, head of Iran's Atomic Energy Organisation earlier on Sunday and had talks with his Iranian counterpart Mohammad Javad Zarif on Saturday.